Ignore is exactly what the name implies. It doesn’t “throw away” something you don’t need instead, it ignores the amount of characters you specify when you call it, up to the char you specify as a breakpoint. It works with both input and output buffers. Essentially, for std::cin statements you use ignore before you do … Read more
Well you always will have an infinite loop, but I know what you really want to know is why cin doesn’t keep prompting for input on each loop iteration causing your infinite loop to freerun. The reason is because cin fails in the situation you describe and won’t read any more input into those variables. … Read more
If you’re using getline after cin >> something, you need to flush the newline out of the buffer in between. My personal favourite for this if no characters past the newline are needed is cin.sync(). However, it is implementation defined, so it might not work the same way as it does for me. For something … Read more
cout << “Enter the number: “; int number; cin >> number; cin.ignore(256, ‘\n’); // remaining input characters up to the next newline character // are ignored cout << “Enter names: “; string names; getline(cin, names);
I would prefer the C++ size constraints over the C versions: // Ignore to the end of file std::cin.ignore(std::numeric_limits<std::streamsize>::max()) // Ignore to the end of line std::cin.ignore(std::numeric_limits<std::streamsize>::max(), ‘\n’)
The cin.clear() clears the error flag on cin (so that future I/O operations will work correctly), and then cin.ignore(10000, ‘\n’) skips to the next newline (to ignore anything else on the same line as the non-number so that it does not cause another parse failure). It will only skip up to 10000 characters, so the … Read more
It doesn’t “fail”; it just stops reading. It sees a lexical token as a “string”. Use std::getline: #include <string> #include <iostream> int main() { std::string name, title; std::cout << “Enter your name: “; std::getline(std::cin, name); std::cout << “Enter your favourite movie: “; std::getline(std::cin, title); std::cout << name << “‘s favourite movie is ” << title; … Read more
You need to check each case individually using the OR operator if you want to check more than one case. if (BothMods == “Yes” || BothMods == “YES” || BothMods == “yes”) { // do whatever }
This is one of the few cases where I’d say a regex is by far your best solution. You could use a regex like: ^\s*([a-zA-Z]+)\s*(\d+)\s*$ Then use regex_match to check it. So for an input string foo: smatch bar; if(regex_match(foo, bar, regex{“^\\s*([a-zA-Z]+)\\s*(\\d+)\\s*$”})) { cout << “OK: ” << bar[1] << ‘\t’ << bar[2] << endl; … Read more
The underlying problem here is that you don’t know in advance how many integers are going to come in, so you can’t use that for loop — there’s no sensible value for numbers. Instead, keep reading values until the end of the input: while (std::cin >> i) sum += i; When the attempted read eventually … Read more